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2024.12.06

Investigating the Squeezed Limit of Primordial Non-Gaussianity: New Constraints from CMB Anisotropies [EN]

<p>The Primordial non-Gaussianity provides fundamental insights into the early Universe and constitutes a crucial area of research in contemporary cosmology. Recently, we extended the cosmological analysis presented in Ibitoye2024 beyond the intergalactic medium (IGM) to investigate the primordial non-Gaussianity parameter (f^0_NL) in the squeezed limit, using the auto- and cross-power spectra of ...</p>

2024.11.29

The research of dark matter halos with galaxy-galaxy lensing method

<p>In the standard LambdaCDM cosmological framework, cosmic structures grow through a hierarchical process. As fundamental building blocks of the dark matter universe, halos are believed to follow a self-similar structure distribution. Thus, we could stacking the weak lensing signal of multiple halos with the galaxy-galaxy lensing (gglens) method, and obtain the average profile of halos. (A.) With...</p>

2024.11.22

On the Role of Structural Bimodality on Galaxy Quenching in Local Universe [EN]

<p>Observations have shown that the termination of the star-forming activity in galaxies (quenching of star formation) is closely related to the structure of the galaxies, in the sense that passive galaxies tend to possess more compact structure. The surface mass density in the core region effectively describes the compactness of galaxies, and therefore have served to be one of the most sensitive ...</p>

2024.11.15

Halo Responses to Baryonic Mechanisms at Small Scale [EN]

<p>The Voids-within-Voids-within-Voids (VVV) project developed a series of extremely high-resolution N-body simulations to study haloes over the entire range of ΛCDM halo masses, from Earth mass to the largest clusters. In this talk, I will present our latest results about how baryons could modify these results for haloes with masses between 10^4 and 10^7 M_sun, below the threshold for galaxy for...</p>

2024.11.08

A study on Kinematical Small-scale Fluctuations Vary with Galaxy Surface Density

<p>Massive galaxies usually observed as symmetric stellar motions and can be fitted well by the commonly used symmetric dynamical models. However, the stellar kinematics of many low-mass galaxies typically contain lots of small patches, causing the stellar second moment of velocity distribution to be non-smooth in small-scales and far from symmetry, we call these patches kinematical small-scale fl...</p>

2024.11.01

Finding QPE-like systems in MOCCA simulation

<p>QPE(Quasi Periodic Eruptions) is new type of &nbsp;X-ray transient event first observed in 2018. It&#39;s characterized by the periodic X-ray outbursts in contrast to its quiescent radiation. One of the proposed model for QPE events involves a secondary body orbiting around the central massive black hole, generating periodic flares as the mass of the secondary object accretes onto the BH. These systems ...</p>

2024.10.25

Galaxy Cluster Studies in the Era of High-resolution X-ray Spectroscopy

<p>Galaxy clusters, as massive, virialized halos within the cosmic web, serve as ideal laboratories for advancing our understanding of cosmology, plasma physics, and the nature of dark matter. High-resolution spectroscopy in soft X-rays will open a new window to map multiphase gas in galaxy clusters and probe physics of the intracluster medium, including but not limited to chemical enrichment hist...</p>

2024.10.18

Gravitational Lensing in the Kerr Spacetime: An Analytic Approach for Light and High-Frequency Gravitational Waves

<p>Current efforts of the Event Horizon Telescope aim at resolving the black hole shadow, mainly with the goal to probe the nature of the black hole and thus the underlying theory of gravity. Here, including other lensing features, in particular multiple images either of individual sources or in form of the so-called photon rings, will allow to place much tighter constrains on the spacetime parame...</p>

2024.10.11

Investigating the link between the growth of SMBHs and their host galaxies with X-ray surveys

<p>X-ray surveys have been an effective way to study growing supermassive black holes (SMBHs). Utilizing X-ray survey fields that have extensive multiwavelength data coverage, we can probe how SMBH growth links with the properties of their host galaxies, which will ultimately help to investigate the physical mechanisms behind the potential coevolution of SMBHs and their hosts. In my talk, I will p...</p>

2024.09.27

AGN SED Modeling: AGN luminosity in the simulated universe and implications on the era of reionization

<p>The study of the spectral energy distribution (SED) of active galactic nuclei (AGN) plays an important role in several aspects of the evolution of the galaxy. In this work, we model the black hole (BH) accretion flow for a wide range of BH mass and accretion rate. The accretion flow is divided into two regimes based on the Eddington-normalized accretion rate value - the ADAFs for low accretion ...</p>